One slightly more succint (perhaps "elegant" even) way of implementing this part of your second approach 
my $in;  $in .= '?, ' for @ins;

# discard hanging comma
$in =~ s/, $//;

[download]
is to say 
my $in = join ', ', ('?') x @ins;

[download]
But actually I have a question on your first approach. Does it actually work? I've been trying it here, passing a string of comma separated numeric values as the bind value for a single placeholder in an IN clause, and in my case (MySQL 4.1, DBD::mysql 2.9007) it seems to just take the first value in the list. Can you post some more sample code and output to show how this works? I ask because it seems like it shouldn't work; that is, it shouldn't let you pass multiple values for a single placeholder.

In reply to Re: DBI and variable numbers of bind parameters by Errto
in thread DBI and variable numbers of bind parameters by friedo

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